French President Emmanuel Macron said on Thursday the United States should not prevent other nations from keeping the 2015 Iran nuclear deal, urging G7 leaders to stand up to the threat of a new “hegemony” by US President Donald Trump.

“You (Trump) are not comfortable with an agreement signed by your predecessor, maybe just because it was signed by your predecessor (Barack Obama), but don’t stop others from respecting it and don’t push Iran to leave. That is the best option we have today," Macron said at the joint press conference with Canadian Prime Minister Justin Trudeau who is hosting the G7 summit in Quebec.

However, Macron apparently did not also rule out amending the deal by what he called reaching a “broader agreement” with the Islamic Republic, which would particularly cover its activities in the region.

“We will have to work all together on a broader agreement with Iran and [other] countries in the region, our allies,” he said, apparently referring to the Persian Gulf monarchies.

We have to look at the future there, we have to look at what happens in Syria, Iraq and Lebanon and we have to find a way to work in this extremely tense context,” he added.

At the same time, Macron expressed support for Trump in his expected summit with the North Korean leader Kim Jong-un, but also warned that the US president’s abrogation last month of the multilateral deal on the Iranian nuclear program, cast doubt on the credibility of such agreements.

The Trump administration has threatened to impose sanctions against European companies that continue to do business with Tehran, an effort the European Union has said it will resist.

Leaders of G7 nations meeting in Canada from Friday are more divided than at any time in the group’s 42-year history, with Trump’s “America First” policies at risk of causing a global trade war and deep diplomatic schisms.

Trump has already imposed hefty tariffs on steel and aluminum imports and threatened to do the same for cars. His decisions to withdraw from the nuclear deal with Iran and a global climate change accord have also fueled tensions.

Macron called on Germany, the UK, Italy, Japan, and Canada, the rest of the body’s membership, to withstand a potential US slide towards “further isolationism and crude hegemony.”

“I believe in cooperation and multilateralism because I will resist hegemony with all my strength. Hegemony is might makes right. Hegemony is the end of the rule of law,” he asserted.

'No leader is forever'

Macron said if Trump doesn't care about "being isolated," then G7 may be better being G6. When reporters asked Macron if the problem with Trump was that he “didn’t care” about being isolated, Macron struck a hostile tone, reminding the media that no president “is forever.”

"The six countries of the G7 without the United States, are a bigger market taken together than the American market,” Macron said. "Maybe the American president doesn't care about being isolated today, but we don't mind being six, if needs be.”

Macron also berated Trump for imposing "unproductive" tariffs on imported steel and aluminum rather than go through international arbitration.

“You can’t, among allies in this international context, start a trade war. For me it’s a question of principle,” the French head of state said.

“Instead of tailoring the statement to Washington’s expectations, the allies had to come up with one that enshrines common values,” Macron said.

With the leaders of the Group of Seven industrialized democracies due in Quebec, Canada's Trudeau warned Trump that they would not roll over on trade tariffs.

He described the US tariffs as “unilateral and illegal” and a national security pretext, which Trump has offered for imposing them, as “risible.”

He added that Trump’s unacceptable actions are going to harm his own citizens. “It is American jobs that are going to be lost because of the actions of this administration,” the Canadian prime minister said.

Trump lashed out at Canada and the EU on Friday and said he plans to leave the G7 early.

"Looking forward to straightening out unfair Trade Deals with the G-7 countries. If it doesn’t happen, we come out even better!" Trump tweeted early Friday morning before he was to leave Washington for Quebec.

Europe urged to stand united

German Economy Minister Peter Altmaier on Friday called for Europe to remain unified in the face of rising trade tensions with the United States, saying it was unclear how the summit of the G7 would end.

“We have a serious situation, not just since last night or this morning, but rather the entire last few weeks,” Altmaier told broadcaster ZDF.

He underlined the importance of European unity on free trade and economic interests.

Altmaier said the EU had long resisted imposing tariffs of its own but had shown it would do so if left with no other choice.